#include <stdio.h>
#include <unistd.h>

// printf("process begin...\n");
// execl("/usr/bin/ls","ls","-a","-l",NULL);
// printf("process end...\n");

int main()
{
    printf("调用say_hello\n");
    execlp("ls", "ls", NULL);
    printf("调用say_hello完毕\n");
    return 0;
}